6-millimeter band
The only exclusively amateur EHF band, requiring home-built equipment.
The 6-millimeter band, also known as 47 GHz, covers 47.0 to 47.2 GHz in the EHF (microwave) radio spectrum. It is set aside internationally for amateur radio and amateur satellite use. Because no commercial off-the-shelf radios exist for this band, amateurs have to design and build their own gear. This is the only EHF band where amateurs have exclusive use—no other radio services share it—and it is the only band above 2 meters that belongs entirely to amateur services.
- Frequency range
- 47.0 GHz to 47.2 GHz
- Narrow band calling frequency
- 47.0882 GHz
- Propagation beacon frequency
- 47.088 GHz
- World distance record
- 344.8 km (214.2 mi) by AD6FP and W6QIW on September 19, 2015
- Uk distance record
- 203 km (126 mi) by GM7MRF/GM0HNW and GW0IVA on October 21, 2001
- Australia distance record
- 181.2 km (112.6 mi) by VK5KK/3 and VK5ZD/3 on November 14, 2019
- Earth-moon-earth record
- 9,967 km (6,193 mi) by AD6FP and RW3BP on January 23, 2005
Lore & Background
The 6-millimeter band is allocated by the International Telecommunication Union to amateur radio and amateur satellites on a primary basis in all three ITU regions. It is notable as the only EHF band amateurs do not share with other radio services, and the only band above 2 meters exclusively for amateur services in its entirety. Amateurs often use the band to experiment with the maximum communication distance they can achieve, and they also use it occasionally for radio contesting. In some areas, amateurs maintain 47 GHz propagation beacons on mountain tops. The band has been successfully used by amateurs in moon bounce contacts.
Reader's Guide
The 6-millimeter band holds a unique place in amateur radio as the only EHF band allocated exclusively to amateur services, with no sharing with other radio services. This exclusivity, combined with the lack of commercial off the shelf radios, means that operators must design and construct their own equipment, fostering a culture of technical experimentation and innovation. The band is used for pushing the limits of communication distance, with world records set across continents. Notable achievements include a 344.8 km terrestrial distance record set by US stations AD6FP and W6QIW, and a 9,967 km Earth-Moon-Earth contact between AD6FP and RW3BP. The band also supports propagation beacons, often placed on mountain tops, and is used in radio contesting. Its narrow band calling frequency is 47.0882 GHz, and propagation beacons operate at 47.088 GHz. The band's legacy is one of technical self-reliance and pioneering microwave communication, with amateurs worldwide contributing to distance records and propagation studies.
Did You Know?
- The world distance record on 6 mm is 344.8 km, set by AD6FP and W6QIW on September 19, 2015.
- The Earth-Moon-Earth record on 6 mm is 9,967 km, set by AD6FP and RW3BP on January 23, 2005.
- Amateurs must design and construct their own equipment for the 6 mm band due to a lack of commercial off the shelf radios.
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